<...  bridge ported 13B in GT-2 was 305 HP at 9,300 RPM with two 44MM chokes in a Webber 48 IDA ... as in E production cars, 235 HP at 9000 RPM with 38MM chokes ....>

Does anyone know how much power these engines produce at our operating ranges of 6500 RPM or so?  What are 44,48 mm chokes?
Just wonderin' ... Jim S.

 
As of last September, The bridge ported 13B in GT-2 was 305 HP at 9,300 RPM with two 44MM chokes in a Webber 48 IDA,  as in GT-2 cars. Darryl Drummond. Probably needed 325 to be competitive. For street ported 13Bs (bigger stock looking port). as in E production cars, 235 HP at 9000 RPM with 38MM chokes.
Stan Lusarski or Darryl Drummond.

The E engines use the stock 2 piece seals. No problems. Peak power available for about 2 hours.  So a fresh engine per weekend. Or if you have no money, (like my operation) a fresh engine every summer.

At 6,500 RPM with good oil temps and pressure, these engines will outlast the airplane.